S. thermophilus strains are used extensively alone or in combination with other S. thermophilus strains or in combination with other microorganisms for the production of fermented food products. For instance, they are included in the formulation of the starter cultures used for yogurt production. Strains of S. thermophilus are expected to participate in the formation of lactic curd by acidification of milk and in the development of the texture of the fermented product. S. thermophilus strains are thus generally characterized by their functional properties, i.e. their acidifying and texturizing properties. A texturizing strain is a strain enabling to obtain fermented milks which can be described by their rheological properties, such as viscosity and ropiness. The texturizing S. thermophilus strains known to date can be classified in three groups based on these rheological properties: 1) high viscosity and high ropiness, 2) low viscosity and low ropiness and 3) average viscosity and ropiness. However, it would be interesting to have a strain of S. thermophilus having rheological properties enabling to obtain fermented milks having a high viscosity and a low ropiness.
Thus one of the problems the invention proposes to resolve is to provide novel strains of S. thermophilus which produce fermented milks having a high viscosity and a low ropiness.